Regulation of human T cell proliferation by IL-7.
The regulation of human T cell proliferation by rIL-7 was investigated. Purified peripheral blood T cells were stimulated to proliferate in a short-term assay by IL-7 in the presence of CD3 mAb or lectin. This stimulation was accompanied by a significant increase in the expression of IL-2R on both CD4+ and CD8+ T cells over that seen with mitogen alone. The proliferation of these cells in the presence of exogenous IL-7 involved both IL-2-dependent and - independent mechanisms as shown by the ability of neutralizing IL-2 antibody to partially inhibit the response. Anti-IL-4 and anti-IL-6 antibodies had no effect on IL-7-induced T cell growth. These results suggest that the costimulatory effect of IL-7 on human T cells is primarily direct, not involving other intermediate T cell growth factors. IL-7 was also found to be mitogenic in a long-term assay in the absence of any costimulus, with the onset of proliferation occurring later than that seen in the presence of mitogen. These results demonstrate that IL-7 provides a potent T cell stimulus either alone or in the presence of co-mitogen and, although this stimulus is accompanied by an increase in the level of IL-2R expression, it is not dependent on the action of IL-2 for its effect.
Armitage
R J
RJ
Immunex Corporation, Seattle, WA 98101.
Namen
A E
AE
Sassenfeld
H M
HM
Grabstein
K H
KH
D002478:Cells, Cultured; D004357:Drug Synergism; D006801:Humans; D066298:In Vitro Techniques; D015851:Interleukin-7 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008934:Mitogens / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*
D015851:Interleukin-7; D008934:Mitogens; D015375:Receptors, Interleukin-2